Complex urban simulations are often difficult to discuss collectively. Results live on individual screens, in reports, or in digital presentations, making shared immersive interpretation challenging.
The Research Area Sustainable Built Environments (SBE) at Chalmers developed the ACE Mixed Reality Studio to address this problem. The studio combines a physical model of the Chalmers Campus with Mixed Reality visualisation workflows to develop, test and support collaborative analysis and decision-making.
Student assistants are an integral part of the Sustainable Built Environments research area. Currently completing their Master’s degrees, Johan Blomsterberg, Djamila Mamedova, and Arvid Hall support our research in energy-efficient building renovation, data management, and spatial data visualisation.
We sat down to talk to Johan, Djamila and Arvid about their backgrounds and the specific projects they are working on.
Johan Blomsterberg
Johan joined the research group with prior industry experience in green building certification and life cycle assessments. He is currently working on integrating these concepts into the ongoing research at Chalmers to develop building archetypes for energy- and climate-aware renovation planning.
What were you doing before joining the research group?
Johan: “I recently completed an internship in London where I worked on future-proofing assets through green building certification, net-zero carbon strategies, energy optimisation, and life cycle assessments (LCA).”
How did that practical experience lead you to Sustainable Built Environments at Chalmers?
Johan: “When I returned to Sweden to complete my master’s studies, I realised that joining the Sustainable Built Environments research area at Chalmers would allow me to build on this practical experience within an academic setting.”
What are you hoping to achieve during your time here?
Johan: “It offered a valuable opportunity to further develop and apply my knowledge, particularly in optimizing asset management workflows from a research-driven perspective.”
Djamila Mamedova
Djamila works alongside Johan on the project Renovation strategy support for building portfolios from a life cycle perspective based on machine learning.
What sparked your interest in joining the research area?
Djamila: “I’ve been curious about research, especially when it relates to sustainability.”
How does working with this research connect to your wider education?
Djamila: “Collecting and understanding data to develop systems and solutions for the built environment feels tangible, and it directly connects to what I’m learning in my studies. I’ve already learned a lot.”
Could you describe the main focus of your current project?
Djamila: “The project focuses on surveying existing building stock and developing a system to evaluate renovation strategies for optimising building performance at scale.”
What is the ultimate aim of developing this evaluation system?
Djamila: “The long term goal is to integrate machine learning to support data driven decision making, enabling more efficient, sustainable renovations with significant impact on energy use and environmental performance.”
Arvid Hall
Arvid works on the development of the ACE Mixed Reality Studio, a platform that uses physical models and digital projection to support collaborative urban planning.
Why did you decide to take on a role as a student assistant?
Arvid: “After an internship year before starting my Master’s, I felt motivated to continue working alongside my studies. I heard about the opportunity to join Sustainable Built Environments and it sounded like a good fit.”
How has the experience been so far?
Arvid: “Here I get to be part of some really interesting research projects and work with some very talented people. It’s also easy to combine with my studies since it’s located in the same building and the hours are flexible.”
What does your day-to-day work on the project involve?
Arvid: “I have mainly been working on a 3D-printed model of the Chalmers campus for the ACE Mixed Reality studio, together with an automated workflow for generating similar models of any location.”
How is this physical model utilised by the research group?
Arvid: “The physical model is used for presentations, where immersive and interactive data can be projected onto it. We are currently exploring how and in what areas this adds value compared to more traditional ways of presenting similar data.”
Complex urban simulations are often difficult to discuss collectively. Results live on individual screens, in reports, or PowerPoint presentations, making shared immersive interpretation challenging.
The Research Area Sustainable Built Environments (SBE) at Chalmers developed the ACE Mixed Reality Studio to address this problem. The studio combines a physical model of the Chalmers Campus with Mixed Reality visualisation workflows to develop, test and support collaborative analysis and decision-making.
The Vision: Making the Invisible Visible
In sustainable urban research, we often simulate futures that nobody in the room can quite see. We face a “black box” problem: sophisticated simulations yield important data, but when results live only in spreadsheets, dashboards, or PowerPoint slides, stakeholders struggle to engage. Too often, the most critical insights never make it into the room where decisions are actually made.
In 2020, Associate Professor Alexander Hollberg (PI) began articulating the need for something more specific than a new visualisation technique. Table-based models and immersive environments were not new. What was missing was a dedicated space at Chalmers: a lab where digital urban methods could be tested, demonstrated, and developed collaboratively, rather than remaining as isolated prototypes or one-off demonstrations.
Before we committed to a physical model, we explored the digital bits. Through the DTCC Twinable project, with Liane Thuvander, we tested the waters in Virtual Reality.
Early explorations in the Twinable project: Procedural VR environments from real-world data.
While technically impressive, these VR experiences revealed a persistent tension: the more immersive the headset became, the more socially distant the room felt. Stakeholders were cut off from non-verbal cues and tactile interaction, making collective decision-making difficult.
In search of a shared medium, we collaborated with Universeum Vislab and Jonas Boström to visualise our research data on their exhibition table. This was a revelation. Seeing our data narrative unfold on a physical map demonstrated the immense power of storytelling in communicating complex urban issues. It allowed stakeholders to stand together, point out, and discuss issues.
The Universium vislab Urban Model of Gothenburg
However, relying on an external exhibition model limited our ability to iterate. We couldn’t just print a new district or change the code overnight. We realised that to truly prototype new solutions, we needed this infrastructure in-house. With advice from Infravis and Linköping University, who helped develop the Universeum model, we began planning our own solution.
Why a Table?
Why, in an age of AI and immersive headsets, do we return to a physical table?
Because complex urban decisions are rarely made by one person, they are social processes. A table is inherently democratic; it allows multiple people to view the same data from different angles simultaneously. It grounds abstract metrics in a physical reality that everyone in the room can agree on – A boundary object. When you project a heat map onto a physical model, it stops being a chart and becomes a place.
The Material as a Character
The goal was clear: build a physical platform that could host digital data. We started by consulting the experts at our own A-verkstad. Jarkko Nordlund and Tabita Nilsson gave us the confidence that we could manufacture the model in-house.
Choosing the material was not a trivial decision. Whatever we printed would become both a research instrument and a projection surface. It needed to be precise, neutral, robust, and reproducible.
AddNorth EPLA Economy turned out to be an ideal solution. Beyond being 100% corn-based and Swedish-made, its matte white finish acts as a perfect canvas for projection mapping. It reflects light neutrally without the specular highlights you might get from PETG or ABS, effectively becoming a physical screen.
In practice, this meant we could treat the physical model not as a fragile artefact, but as an everyday research instrument: handled, reconfigured, and reused without much hassle.
Close-up of the 3D printed tiles showing the reinforcement ribs and magnet positions.
Aiming for Modularity
Building the physical model wasn’t just about printing; it was a design challenge led by Sanjay Somanath. “We didn’t want a static sculpture; we wanted a system that could grow with the campus.” says Sanjay.
Early CAD models of the MR Table showing the tiling system and the detailed buildings.
Sara Abouebeid provided a detailed base model of the Chalmers Campus, which included landmark buildings such as the Johanneberg Science Park, the climbing hall, and the Chalmers ACE building. The next step was to design a scalable tiling system. Our initial designs used a dovetail locking mechanism.
In late 2025, Master’s student Arvid Hall joined the team as a student assistant and identified a critical flaw: the dovetails required vertical insertion. To replace a single central tile, you had to dismantle the entire surrounding neighbourhood. Arvid prototyped a wide range of alternatives, experimenting with rods, buttons, and various radii, before settling on a robust slotting tab system.
This seemingly small change, from dovetails to lateral slots, meant that the model could behave like a living system rather than an artefact. It allowed us to swap out a “2025” building tile for a “2030” proposal in seconds, without disrupting the rest of the neighbourhood.
The advantage of this code-driven approach is its universality. We can generate a physical-digital twin for any location in Sweden, from a single city block to an entire municipality, almost entirely automatically.
PowerPoint as a Projection Engine
While the printer nozzles were busy, the digital team was solving the other half of the puzzle: the projection.
Vasilis Nasarentin (DTCC) and Fabio Latino (Infravis) supported the development of the pipeline. Aiming for a “Minimum Viable Product,” our first projection system was… PowerPoint!
It allowed us to prove the concept and test the readability of text, colour reproduction and animations at 1:1250 scale without writing a line of code. Once validated, we moved to a full-fledged web app.
Real-time 2D Lattice Boltzmann CFD simulation projected onto the table.
Simultaneously, PhD student Jieming Yan is developing Augmented Reality (AR) prototypes to layer building performance data directly onto the physical model. You first see the physical context, but holding up a tablet reveals the invisible energy metrics.
Technical details
The Software Stack
We deliberately moved away from heavy game engines like Unity or Unreal Engine at this initial stage to ensure accessibility and rapid prototyping:
MapLibre GL JS: Handles core map rendering and vector tiles.
Three.js: Handles the real-time shadows.
GeoTIFF.js: Enables client-side processing of heavy DEM rasters for stormwater simulations.
BroadcastChannel API: Decouples the interface, allowing a presenter to drive the visualisation from a tablet while walking around the table.
The Calibration Challenge
We avoided expensive mesh-warping software by leveraging the web stack. We built a “Grid Animation” layer: a projection of the physical tile boundaries. We manually adjust the digital camera in the web app until the hologram overlaps the physical seams, saving the configuration to a JSON file.
The Data Pipeline
The pipeline is built on the open-source DTCC Platform.
Automated Tiling: We utilise Blender in headless mode to automatically slice the large city mesh into standard 20cm × 20cm tiles.
Magnet Integration: We learned a hard lesson during prototyping: standard N52 neodymium magnets were too strong and often ripped out of their housings. We switched to slightly weaker magnets, which provided the perfect balance of holding force and durability.
AR Tracking
Tracking on a featureless white surface is difficult. To simplify this problem, Jieming Yan used Fologram and Rhino Grasshopper. Pre-simulated results are stored locally, and the visualisation is synchronised to a handheld device through a Grasshopper–Fologram workflow. Once data loading and occlusion challenges are addressed, QR-based reference markers are used to align the virtual and physical models. “Once scaled and aligned, the digital model remains spatially registered with the physical one, allowing building-performance data to be explored in its physical context.” says Jieming Yan.
A Canvas for Discussion
A table needs a home. Henriette Söderberg, Angela Sasic Kalagadis, and Elisabeth Meyer helped us transform “SB-488”, a standard meeting room, into a dedicated studio with controlled lighting and ceiling-mounted projection.
The true test of the studio is in its use. As Ida Gäskeby (Chalmers Fastigheter) noted during our testing:
“This is a very different type of thing than just watching a PowerPoint… with this table we can show information at different levels of knowledge… and discuss important decisions.”
An Invitation
We are just getting started. The ACE Mixed Reality Studio is not a finished system, but a shared platform for experimentation.
If your research produces maps that are hard to explain, simulations that stay stuck on laptops, or results that disappear into reports, this table is for you.
We are looking for partners to push the boundaries of this platform. If you have urban data and ideas for visualisation, come visit us for a demo!
